chore(deps): update dependency pymdown-extensions to >=10.18,<10.19 (#447)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

setup.py

@@ -18,7 +18,7 @@
     "portray",
     "mkdocs-material-extensions>=1.0.3",
     "pygments>=2.19,<2.20",
-    "pymdown-extensions>=10.17,<10.18",
+    "pymdown-extensions>=10.18,<10.19",
 ]
 
 install_requires = [